Myocardial ischemia-reperfusion induced cardiac extracellular vesicles harbour proinflammatory features and aggravate heart injury

Small extracellular vesicles associated miRNA in myocardial fibrosis

Myocardial fibrosis involves the loss of cardiomyocytes, myocardial fibroblast proliferation, and a reduction in angiogenesis, ultimately leading to heart failure, Given its significant implications, it is crucial to explore novel therapies for myocardial fibrosis. Recently one emerging avenue has been the use of small extracellular vesicles (sEV)-carried miRNA. In this review, we summarize the regulatory role of sEV-carried miRNA in myocardial fibrosis. We explored not only the potential diagnostic value of circulating miRNA as biomarkers for heart disease but also the therapeutic implications of sEV-carried miRNA derived from various cellular sources and applications of modified sEV. This exploration is paramount for researchers striving to develop innovative, cell-free therapies as potential drug candidates for the management of myocardial fibrosis.

Role of macrophage polarization in heart failure and traditional Chinese medicine treatment

Heart failure (HF) has a severe impact on public health development due to high morbidity and mortality and is associated with imbalances in cardiac immunoregulation. Macrophages, a major cell population involved in cardiac immune response and inflammation, are highly heterogeneous and polarized into M1 and M2 types depending on the microenvironment. M1 macrophage releases inflammatory factors and chemokines to activate the immune response and remove harmful substances, while M2 macrophage releases anti-inflammatory factors to inhibit the overactive immune response and promote tissue repair. M1 and M2 restrict each other to maintain cardiac homeostasis. The dynamic balance of M1 and M2 is closely related to the Traditional Chinese Medicine (TCM) yin-yang theory, and the imbalance of yin and yang will result in a pathological state of the organism. Studies have confirmed that TCM produces positive effects on HF by regulating macrophage polarization. This review describes the critical role of macrophage polarization in inflammation, fibrosis, angiogenesis and electrophysiology in the course of HF, as well as the potential mechanism of TCM regulation of macrophage polarization in preventing and treating HF, thereby providing new ideas for clinical treatment and scientific research design of HF.

Tipifarnib Reduces Extracellular Vesicles and Protects From Heart Failure

BACKGROUND

Heart failure (HF) is one of the leading causes of mortality worldwide. Extracellular vesicles, including small extracellular vesicles or exosomes, and their molecular cargo are known to modulate cell-to-cell communication during multiple cardiac diseases. However, the role of systemic extracellular vesicle biogenesis inhibition in HF models is not well documented and remains unclear.

METHODS

We investigated the role of circulating exosomes during cardiac dysfunction and remodeling in a mouse transverse aortic constriction (TAC) model of HF. Importantly, we investigate the efficacy of tipifarnib, a recently identified exosome biogenesis inhibitor that targets the critical proteins (Rab27a [Ras associated binding protein 27a], nSMase2 [neutral sphingomyelinase 2], and Alix [ALG-2-interacting protein X]) involved in exosome biogenesis for this mouse model of HF. In this study, 10-week-old male mice underwent TAC surgery were randomly assigned to groups with and without tipifarnib treatment (10 mg/kg 3 times/wk) and monitored for 8 weeks, and a comprehensive assessment was conducted through performed echocardiographic, histological, and biochemical studies.

RESULTS

TAC significantly elevated circulating plasma exosomes and markedly increased cardiac left ventricular dysfunction, cardiac hypertrophy, and fibrosis. Furthermore, injection of plasma exosomes from TAC mice induced left ventricular dysfunction and cardiomyocyte hypertrophy in uninjured mice without TAC. On the contrary, treatment of tipifarnib in TAC mice reduced circulating exosomes to baseline and remarkably improved left ventricular functions, hypertrophy, and fibrosis. Tipifarnib treatment also drastically altered the miRNA profile of circulating post-TAC exosomes, including miR 331-5p, which was highly downregulated both in TAC circulating exosomes and in TAC cardiac tissue. Mechanistically, miR 331-5p is crucial for inhibiting the fibroblast-to-myofibroblast transition by targeting HOXC8, a critical regulator of fibrosis. Tipifarnib treatment in TAC mice upregulated the expression of miR 331-5p that acts as a potent repressor for one of the fibrotic mechanisms mediated by HOXC8.

CONCLUSIONS

Our study underscores the pathological role of exosomes in HF and fibrosis in response to pressure overload. Tipifarnib-mediated inhibition of exosome biogenesis and cargo sorting may serve as a viable strategy to prevent progressive cardiac remodeling in HF.

Chiral Supramolecular Nanofibers Regulated Tumor-Derived Exosomes Secretion for Constructing an Anti-Tumor Extracellular Microenvironment

Tumor-derived exosomes (TDEs) induced extracellular microenvironment has recently been validated to be critical for tumor progression and metastasis, however, remodeling it for oncotherapy still remains a major challenge due to difficulty in regulation of TDEs secretion. Herein, the supramolecular chiral nanofibers, composed of L/D-phenylalanine derivates (L/D-Phe) and linear hyaluronic acid (HA), are successfully employed to construct TDEs induced anti-tumor extracellular microenvironment. The left-handed L-Phe @HA nanofibers significantly inhibit TDEs secretion into extracellular microenvironment, which results in suppression of tumor proliferation and metastasis in vitro and vivo. Biological assays and theoretical modeling reveal that these results are mainly attributed to strong adsorption of the key exosomes transporters (Ras-related protein Rab-27A and synaptosome-associated protein 23) on left-handed L-Phe @HA nanofibers via enhanced stereoselective interaction, leading to degradation and phosphorylated dropping of exosomes transporters. Subsequently, transfer function of exosomes transporters is limited, which causes remarkable inhibition of TDEs secretion. These findings provide a promising novel insight of chiral functional materials to establish an anti-tumor extracellular microenvironment via regulation of TDEs secretion.

Cardiac-derived extracellular vesicles improve mitochondrial function to protect the heart against ischemia/reperfusion injury by delivering ATP5a1

BACKGROUND

Numerous studies have confirmed the involvement of extracellular vesicles (EVs) in various physiological processes, including cellular death and tissue damage. Recently, we reported that EVs derived from ischemia-reperfusion heart exacerbate cardiac injury. However, the role of EVs from healthy heart tissue (heart-derived EVs, or cEVs) on myocardial ischemia-reperfusion (MI/R) injury remains unclear.

RESULTS

Here, we demonstrated that intramyocardial administration of cEVs significantly enhanced cardiac function and reduced cardiac damage in murine MI/R injury models. cEVs treatment effectively inhibited ferroptosis and maintained mitochondrial homeostasis in cardiomyocytes subjected to ischemia-reperfusion injury. Further results revealed that cEVs can transfer ATP5a1 into cardiomyocytes, thereby suppressing mitochondrial ROS production, alleviating mitochondrial damage, and inhibiting cardiomyocyte ferroptosis. Knockdown of ATP5a1 abolished the protective effects of cEVs. Furthermore, we found that the majority of cEVs are derived from cardiomyocytes, and ATP5a1 in cEVs primarily originates from cardiomyocytes of the healthy murine heart. Moreover, we demonstrated that adipose-derived stem cells (ADSC)-derived EVs with ATP5a1 overexpression showed much better efficacy on the therapy of MI/R injury compared to control ADSC-derived EVs.

CONCLUSIONS

These findings emphasized the protective role of cEVs in cardiac injury and highlighted the therapeutic potential of targeting ATP5a1 as an important approach for managing myocardial damage induced by MI/R injury.

Interference with GPR4 inactivates NLRP3 inflammasome signaling by inhibiting LPAR1 expression to ameliorate oxygen-glucose deprivation/reoxygenation-induced inflammation and apoptosis of cardiomyocytes

Myocardial ischemia/reperfusion (MI/R) injury is a detrimental disease with high mortality worldwide. We aimed to explore the role of G protein-coupled receptor 4 (GPR4) and lysophosphatidic acid receptor 1 (LPAR1) in MI/R injury in vitro. H9c2 cells were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) conditions to simulate the MI/R injury and GPR4 expression was detected. Then, GPR4 was knocked down and cell viability was examined with a CCK-8 assay. The activities of LDH, CK and CK-MB were detected to evaluate the damage of OGD/R-induced H9c2 cells. ELISA kits and TUNEL staining were used to examine the inflammation and apoptosis of H9c2 cells exposed to OGD/R conditions. Western blot was employed to detect the expression of proteins related to apoptosis and NLRP3 inflammasome signaling. Additionally, Co-IP analyzed the binding between GPR4 and LPAR1. Finally, LPAR1 was overexpressed to conduct the rescue experiments. Results revealed that GPR4 was upregulated in OGD/R-treated H9c2 cells and GPR4 knockdown attenuated the damage of H9c2 cells. OGD/R induced inflammation and apoptosis were markedly inhibited by GPR4 silencing, as evidenced by the decreased TNF-α, IL-6 and IL-8 levels as well as the elevated Bcl-2 expression and reduced Bax and cleaved caspase3 expression. Moreover, GPR4 bound to LPAR1 and upregulated LPAR1 expression. Interference with GPR4 inactivated the NLRP3 inflammasome signaling. Besides, LPAR1 overexpression abrogated the effects of GPR4 silencing on the damage, inflammation and apoptosis of H9c2 cells induced by OGD/R. Particularly, LPAR1 upregulation promoted the activation of NLRP3 inflammasome signaling in GPR4-silenced H9c2 cells induced by OGD/R. To be concluded, GPR4 deficiency inactivates NLRP3 inflammasome signaling by inhibiting LPAR1 expression to ameliorate OGD/R -induced inflammation and apoptosis of cardiomyocytes.

Electroacupuncture pre-treatment exerts a protective effect on LPS-induced cardiomyopathy in mice through the delivery of miR-381 via exosomes

OBJECTIVE

This study aims to investigate the cardiac protective effects and molecular mechanisms of electroacupuncture (EA) pre-treatment in lipopolysaccharide (LPS)-Induced Cardiomyopathy.

METHODS AND RESULTS

Pre-treatment with EA was performed 30 min before intraperitoneal injection of LPS. Cardiac function changes in mice of the EA + LPS group were observed using electrocardiography, echocardiography, and enzyme linked immunosorbent assay (ELISA) and compared with the LPS group. The results demonstrated that EA pre-treatment significantly improved the survival rate of septic mice, alleviated the severity of endotoxemia, and exhibited notable cardiac protective effects. These effects were characterized by a reduction in ST-segment elevation on electrocardiography, an increase in ejection fraction (EF) and fraction shortening (FS) on echocardiography and a decrease in the expression of serum cardiac troponin I (cTn-I) levels. Serum exosomes obtained after EA pre-treatment were extracted and administered to septic mice, revealing significant cardiac protective effects of EA-derived exosomes. Furthermore, the antagonism of circulating exosomes in mice markedly suppressed the cardiac protective effects conferred by EA pre-treatment. Analysis of serum exosomes using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) revealed a significant upregulation of miR-381 expression after EA pre-treatment. Inhibition or overexpression of miR-381 through serotype 9 adeno-associated virus (AAV9)-mediated gene delivery demonstrated that overexpression of miR-381 exerted a cardiac protective effect, while inhibition of miR-381 significantly attenuated the cardiac protective effects conferred by EA pre-treatment.

CONCLUSIONS

Our research findings have revealed a novel endogenous cardiac protection mechanism, wherein circulating exosomes derived from EA pre-treatment mitigate LPS-induced cardiac dysfunction via miR-381.

Roles of extracellular vesicles on macrophages in inflammatory bone diseases

Inflammatory bone disease is a general term for a series of diseases caused by chronic inflammation, which leads to the destruction of bone homeostasis, that is, the osteolytic activity of osteoclasts increases, and the osteogenic activity of osteoblasts decreases, leading to osteolysis. Macrophages are innate immune cell with plasticity, and their polarization is related to inflammatory bone diseases. The dynamic balance of macrophages between the M1 phenotype and the M2 phenotype affects the occurrence and development of diseases. In recent years, an increasing number of studies have shown that extracellular vesicles existing in the extracellular environment can act on macrophages, affecting the progress of inflammatory diseases. This process is realized by influencing the physiological activity or functional activity of macrophages, inducing macrophages to secrete cytokines, and playing an anti-inflammatory or pro-inflammatory role. In addition, by modifying and editing extracellular vesicles, the potential of targeting macrophages can be used to provide new ideas for developing new drug carriers for inflammatory bone diseases.

Navigating the landscape of RNA delivery systems in cardiovascular disease therapeutics

Cardiovascular diseases (CVDs) stand as the leading cause of death worldwide, posing a significant global health challenge. Consequently, the development of innovative therapeutic strategies to enhance CVDs treatment is imperative. RNA-based therapies, encompassing non-coding RNAs, mRNA, aptamers, and CRISPR/Cas9 technology, have emerged as promising tools for addressing CVDs. However, inherent challenges associated with RNA, such as poor cellular uptake, susceptibility to RNase degradation, and capture by the reticuloendothelial system, underscore the necessity of combining these therapies with effective drug delivery systems. Various non-viral delivery systems, including extracellular vesicles, lipid-based carriers, polymeric and inorganic nanoparticles, as well as hydrogels, have shown promise in enhancing the efficacy of RNA therapeutics. In this review, we offer an overview of the most relevant RNA-based therapeutic strategies explored for addressing CVDs and emphasize the pivotal role of delivery systems in augmenting their effectiveness. Additionally, we discuss the current status of these therapies and the challenges that hinder their clinical translation.

Ischemia and reperfusion-injured liver-derived exosomes elicit acute lung injury through miR-122-5p regulated alveolar macrophage polarization

Acute lung injury (ALI) is a common postoperative complication, particularly in pediatric patients after liver transplantation. Hepatic ischemia-reperfusion (HIR) increases the release of exosomes (IR-Exos) in peripheral circulation. However, the role of IR-Exos in the pathogenesis of ALI induced by HIR remains unclear. Here, we explored the role of exosomes derived from the HIR-injured liver in ALI development. Intravenous injection of IR-Exos caused lung inflammation in naive rats, whereas pretreatment with an inhibitor of exosomal secretion (GW4869) attenuated HIR-related lung injury. In vivo and in vitro results show that IR-Exos promoted proinflammatory responses and M1 macrophage polarization. Furthermore, miRNA profiling of serum identified miR-122-5p as the exosomal miRNA with the highest increase in young rats with HIR compared with controls. Additionally, IR-Exos transferred miR-122-5p to macrophages and promoted proinflammatory responses and M1 phenotype polarization by targeting suppressor of cytokine signaling protein 1(SOCS-1)/nuclear factor (NF)-κB. Importantly, the pathological role of exosomal miR-122-5p in initiating lung inflammation was reversed by inhibition of miR-122-5p. Clinically, high levels of miR-122-5p were found in serum and correlated to the severity of lung injury in pediatric living-donor liver transplant recipients with ALI. Taken together, our findings reveal that IR-Exos transfer liver-specific miR-122-5p to alveolar macrophages and elicit ALI by inducing M1 macrophage polarization via the SOCS-1/NF-κB signaling pathway.

Systems Approaches to Cell Culture-Derived Extracellular Vesicles for Acute Kidney Injury Therapy: Prospects and Challenges

Acute kidney injury (AKI) is a heterogeneous syndrome, comprising diverse etiologies of kidney insults that result in high mortality and morbidity if not well managed. Although great efforts have been made to investigate underlying pathogenic mechanisms of AKI, there are limited therapeutic strategies available. Extracellular vesicles (EV) are membrane-bound vesicles secreted by various cell types, which can serve as cell-free therapy through transfer of bioactive molecules. In this review, we first overview the AKI syndrome and EV biology, with a particular focus on the technical aspects and therapeutic application of cell culture-derived EVs. Second, we illustrate how multi-omic approaches to EV miRNA, protein, and genomic cargo analysis can yield new insights into their mechanisms of action and address unresolved questions in the field. We then summarize major experimental evidence regarding the therapeutic potential of EVs in AKI, which we subdivide into stem cell and non-stem cell-derived EVs. Finally, we highlight the challenges and opportunities related to the clinical translation of animal studies into human patients.

Blockade of exosome release alleviates the hypersensitive reaction by influencing the T helper cell population in cow's milk allergic mice

The aim of this work was to evaluate the ameliorative effects of exosome biogenesis in cow's milk allergy (CMA) response. In this context, BALB/c mice were systemically sensitized with cow's milk proteins plus an aluminum adjuvant to induce CMA. The inhibitor GW4869 of exosome biogenesis was added before sensitization and then the anaphylactic reactions were evaluated both in vivo (clinical score and body temperature) and in vitro (serum histamine, allergen-specific antibodies, cytokines by ELISA and cell analysis by flow cytometry) to explore the role of exosomes in the development of CMA. Nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM) showed that the size distribution and morphology of CMA-derived exosomes were not changed after GW4869 preconditioning, and the concentration of exosomes was much lower than that of the CMA group. In the GW4869 group, inhibition of release of exosomes modulated the induction of T helper 2 cell (Th2)-related substances, with a decrease in histamine and allergen-specific immunoglobulin (Ig) E, and the expression of Th1, Th2, and Th17 cells all decreased as well. Moreover, the experimental data were integrated by means of principal component analysis (PCA) to give an overview that the percentage of Th cells and concentrations of cytokines were more influenced by GW4869 treatment. These data for the first time demonstrated that exosomes are involved in the development of CMA and the blockade of exosome release with GW4869 suppressed the IgE-mediated immune response in CMA.

Extracellular vesicles in heart failure

Physiologically, extracellular vesicles (EVs) have been implicated as crucial mediators of immune response, cell homeostasis, angiogenesis, cell differentiation and growth, and tissue repair. In heart failure (HF) they may act as regulators of cardiac remodeling, microvascular inflammation, micro environmental changes, tissue fibrosis, atherosclerosis, neovascularization of plaques, endothelial dysfunction, thrombosis, and reciprocal heart-remote organ interaction. The chapter summaries the nomenclature, isolation, detection of EVs, their biologic role and function physiologically as well as in the pathogenesis of HF. Current challenges to the utilization of EVs as diagnostic and predictive biomarkers in HF are also discussed.

Therapeutic Role of Chinese Medicine Targeting Nrf2/HO-1 Signaling Pathway in Myocardial Ischemia/Reperfusion Injury

Acute myocardial infarction (AMI), characterized by high incidence and mortality rates, poses a significant public health threat. Reperfusion therapy, though the preferred treatment for AMI, often exacerbates cardiac damage, leading to myocardial ischemia/reperfusion injury (MI/RI). Consequently, the development of strategies to reduce MI/RI is an urgent priority in cardiovascular therapy. Chinese medicine, recognized for its multi-component, multi-pathway, and multi-target capabilities, provides a novel approach for alleviating MI/RI. A key area of interest is the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. This pathway is instrumental in regulating inflammatory responses, oxidative stress, apoptosis, endoplasmic reticulum stress, and ferroptosis in MI/RI. This paper presents a comprehensive overview of the Nrf2/HO-1 signaling pathway's structure and its influence on MI/RI. Additionally, it reviews the latest research on leveraging Chinese medicine to modulate the Nrf2/HO-1 pathway in MI/RI treatment.

Closer to The Heart: Harnessing the Power of Targeted Extracellular Vesicle Therapies

Extracellular vesicles (EVs) have emerged as novel diagnostic and therapeutic approaches for cardiovascular diseases. EVs derived from various origins exhibit distinct effects on the cardiovascular system. However, the application of native EVs is constrained due to their poor stabilities and limited targeting capabilities. Currently, targeted modification of EVs primarily involves genetic engineering, chemical modification (covalent, non-covalent), cell membrane modification, and biomaterial encapsulation. These techniques enhance the stability, biological activity, target-binding capacity, and controlled release of EVs at specific cells and tissues. The diverse origins of cardioprotective EVs are covered, and the applications of cardiac-targeting EV delivery systems in protecting against cardiovascular diseases are discussed. This review summarizes the current stage of research on the potential of EV-based targeted therapies for addressing cardiovascular disorders.

High-dose ascorbic acid potentiates immune modulation through STAT1 phosphorylation inhibition and negative regulation of PD-L1 in experimental sepsis

Sepsis is a complex, multifactorial syndrome characterized by a dysregulated host response to infection, leading to severe organ dysfunction and high mortality rates among critically ill patients. Hypovitaminosis C and vitamin C deficiency are frequently observed in septic patients, prompting interest in the potential therapeutic role of ascorbic acid. Although intravenous administration of ascorbic acid has been investigated in multiple clinical trials for sepsis treatment, the specific immunomodulatory mechanisms underlying its effects remain elusive. This study aimed to investigate the protective effects of high-dose ascorbic acid on experimental sepsis. Results show that intravenous administration of high-dose ascorbic acid (250 mg/kg) attenuated sepsis-induced organ dysfunctions in a cecal ligation and puncture (CLP)-induced septic mouse model. Ascorbic acid improved splenic cell apoptosis and increased the number of CD3+ T cells in septic mice induced by CLP. Furthermore, ascorbic acid downregulated PD-L1 expression in livers, reduced PD-1 expression in spleens, and inhibited the phosphorylation of STAT1 at Y701 in multiple organs of CLP-induced septic mice. The in vitro experiments also revealed that 800 μM ascorbic acid suppressed STAT1 phosphorylation and inhibited lipopolysaccharide (LPS) and IFN-γ-induced PD-L1 expression in macrophages. These findings suggest that ascorbic acid prevents sepsis-associated organ dysfunction through the p-STAT1/PD-L1 signaling pathway. Our study provides new insights into the potential therapeutic use of ascorbic acid in sepsis.

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly.

Transcriptomic analysis reveals the lipid metabolism-related gene regulatory characteristics and potential therapeutic agents for myocardial ischemia-reperfusion injury

Background

Impaired energy balance caused by lipid metabolism dysregulation is an essential mechanism of myocardial ischemia-reperfusion injury (MI/RI). This study aims to explore the lipid metabolism-related gene (LMRG) expression patterns in MI/RI and to find potential therapeutic agents.

Methods

Differential expression analysis was performed to screen the differentially expressed genes (DEGs) and LMRGs in the MI/RI-related dataset GSE61592. Enrichment and protein-protein interaction (PPI) analyses were performed to identify the key signaling pathways and genes. The expression trends of key LMRGs were validated by external datasets GSE160516 and GSE4105. The corresponding online databases predicted miRNAs, transcription factors (TFs), and potential therapeutic agents targeting key LMRGs. Finally, the identified LMRGs were confirmed in the H9C2 cell hypoxia-reoxygenation (H/R) model and the mouse MI/RI model.

Results

Enrichment analysis suggested that the "lipid metabolic process" was one of the critical pathways in MI/RI. Further differential expression analysis and PPI analysis identified 120 differentially expressed LMRGs and 15 key LMRGs. 126 miRNAs, 55 TFs, and 51 therapeutic agents were identified targeting these key LMRGs. Lastly, the expression trends of Acadm, Acadvl, and Suclg1 were confirmed by the external datasets, the H/R model and the MI/RI model.

Conclusion

Acadm, Acadvl, and Suclg1 may be the key genes involved in the MI/RI-related lipid metabolism dysregulation; and acting upon these factors may serve as a potential therapeutic strategy.

Extracellular vesicles from normal tissues orchestrate the homeostasis of macrophages and attenuate inflammatory injury of sepsis

Extracellular vesicles (EVs) exist throughout our bodies. We recently revealed the important role of intracardiac EVs induced by myocardial ischemia/reperfusion on cardiac injury and dysfunction. However, the role of EVs isolated from normal tissues remains unclear. Here we found that EVs, derived from murine heart, lung, liver and kidney have similar effects on macrophages and regulate the inflammation, chemotaxis, and phagocytosis of macrophages. Interestingly, EV-treated macrophages showed LPS resistance with reduced expressions of inflammatory cytokines and enhanced phagocytic activity. Furthermore, we demonstrated that the protein content in EVs contributed to the activation of inflammation, while the RNA component mainly limited the excessive inflammatory response of macrophages to LPS. The enrichment of miRNAs, including miR-148a-3p, miR-1a-3p and miR-143-3p was confirmed in tissue EVs. These EV-enriched miRNAs contributed to the inflammation remission in LPS induced macrophages through multiple pathways, including STAT3, P65 and SAPK/JNK. Moreover, administration of both EVs and EV-educated macrophages attenuated septic injury and cytokine storm in murine CLP models. Taken together, the present study disclosed that EVs from normal tissues can orchestrate the homeostasis of macrophages and attenuate inflammatory injury of sepsis. Therefore, tissue derived EVs or their derivatives may serve as potential therapeutic strategies in inflammatory diseases.

Communication Regarding the Myocardial Ischemia/Reperfusion and Cognitive Impairment: A Narrative Literature Review

Coronary artery disease is a prevalent ischemic disease that results in insufficient blood supply to the heart muscle due to narrowing or occlusion of the coronary arteries. Various reperfusion strategies, including pharmacological thrombolysis and percutaneous coronary intervention, have been developed to enhance blood flow restoration. However, these interventions can lead to myocardial ischemia/reperfusion injury (MI/RI), which can cause unpredictable complications. Recent research has highlighted a compelling association between MI/RI and cognitive function, revealing pathophysiological mechanisms that may explain altered brain cognition. Manifestations in the brain following MI/RI exhibit pathological features resembling those observed in Alzheimer's disease (AD), implying a potential link between MI/RI and the development of AD. The pro-inflammatory state following MI/RI may induce neuroinflammation via systemic inflammation, while impaired cardiac function can result in cerebral under-perfusion. This review delves into the role of extracellular vesicles in transporting deleterious substances from the heart to the brain during conditions of MI/RI, potentially contributing to impaired cognition. Addressing the cognitive consequence of MI/RI, the review also emphasizes potential neuroprotective interventions and pharmacological treatments within the MI/RI model. In conclusion, the review underscores the significant impact of MI/RI on cognitive function, summarizes potential mechanisms of cardio-cerebral communication in the context of MI/RI, and offers ideas and insights for the prevention and treatment of cognitive dysfunction following MI/RI.

Mechanisms and therapeutic strategies of extracellular vesicles in cardiovascular diseases

Cardiovascular disease (CVD) significantly impacts global society since it is the leading cause of death and disability worldwide, and extracellular vesicle (EV)-based therapies have been extensively investigated. EV delivery is involved in mediating the progression of CVDs and has great potential to be biomarker and therapeutic molecular carrier. Besides, EVs from stem cells and cardiac cells can effectively protect the heart from various pathologic conditions, and then serve as an alternative treatment for CVDs. Moreover, the research of using EVs as delivery carriers of therapeutic molecules, membrane engineering modification of EVs, or combining EVs with biomaterials further improves the application potential of EVs in clinical treatment. However, currently there are only a few articles summarizing the application of EVs in CVDs. This review provides an overview of the role of EVs in the pathogenesis and diagnosis of CVDs. It also focuses on how EVs promote the repair of myocardial injury and therapeutic methods of CVDs. In conclusion, it is of great significance to review the research on the application of EVs in the treatment of CVDs, which lays a foundation for further exploration of the role of EVs, and clarifies the prospect of EVs in the treatment of myocardial injury.

Transcriptomic Landscape of Circulating Extracellular Vesicles in Heart Transplant Ischemia-Reperfusion

Ischemia-reperfusion injury (IRI) is an inevitable event during heart transplantation, which is known to exacerbate damage to the allograft. However, the precise mechanisms underlying IRI remain incompletely understood. Here, we profiled the whole transcriptome of plasma extracellular vesicles (EVs) by RNA sequencing from 41 heart transplant recipients immediately before and at 12 h after transplant reperfusion. We found that the expression of 1317 protein-coding genes in plasma EVs was changed at 12 h after reperfusion. Upregulated genes of plasma EVs were related to metabolism and immune activation, while downregulated genes were related to cell survival and extracellular matrix organization. In addition, we performed correlation analyses between EV transcriptome and intensity of graft IRI (i.e., cardiomyocyte injury), as well as EV transcriptome and primary graft dysfunction, as well as any biopsy-proven acute rejection after heart transplantation. We ultimately revealed that at 12 h after reperfusion, 4 plasma EV genes (ITPKA, DDIT4L, CD19, and CYP4A11) correlated with both cardiomyocyte injury and primary graft dysfunction, suggesting that EVs are sensitive indicators of reperfusion injury reflecting lipid metabolism-induced stress and imbalance in calcium homeostasis. In conclusion, we show that profiling plasma EV gene expression may enlighten the mechanisms of heart transplant IRI.

Engineered Extracellular Vesicles: A potential treatment for regeneration

Extracellular vesicles (EVs) play a critical role in various physiological and pathological processes. EVs have gained recognition in regenerative medicine due to their biocompatibility and low immunogenicity. However, the practical application of EVs faces challenges such as limited targeting ability, low yield, and inadequate therapeutic effects. To overcome these limitations, engineered EVs have emerged. This review aims to comprehensively analyze the engineering methods utilized for modifying donor cells and EVs, with a focus on comparing the therapeutic potential between engineered and natural EVs. Additionally, it aims to investigate the specific cell effects that play a crucial role in promoting repair and regeneration, while also exploring the underlying mechanisms involved in the field of regenerative medicine.

Extracellular vesicles derived from different tissues attenuate cardiac dysfunction in murine MI models

BACKGROUND

Extracellular vesicles (EVs) derived from various cell sources exert cardioprotective effects during cardiac ischemic injury. Our previous study confirmed that EVs derived from ischemic-reperfusion injured heart tissue aggravated cardiac inflammation and dysfunction. However, the role of EVs derived from normal cardiac tissue in myocardial ischemic injury remains elusive.

RESULTS

In the present study, normal heart-derived EVs (cEVs) and kidney-derived EVs (nEVs) were isolated and intramyocardially injected into mice after myocardial infarction (MI). We demonstrated that administration of both cEVs and nEVs significantly improved cardiac function, reduced the scar size, and alleviated inflammatory infiltration into the heart. In addition, cardiomyocyte apoptosis was inhibited, whereas angiogenesis was enhanced in the hearts receiving cEVs or nEVs treatment. Moreover, intramyocardial injection of cEVs displayed much better cardiac protective efficacy than nEVs in murine MI models. RNA-seq and protein-protein interaction (PPI) network analysis revealed the protective mRNA clusters in both cEVs and nEVs. These mRNAs were involved in multiple signaling pathways, which may synergistically orchestrate to prevent the heart from further damage post MI.

CONCLUSIONS

Collectively, our results indicated that EVs derived from normal heart tissue may represent a promising strategy for cardiac protection in ischemic heart diseases.

Circulating Exosomes Mediate Neurodegeneration Following Hepatic Ischemia-reperfusion Through Inducing Microglial Pyroptosis in the Developing Hippocampus

BACKGROUND

Poor neurodevelopmental outcomes after pediatric liver transplantation seriously affect the long-term quality of life of recipients, in whom hepatic ischemia reperfusion (HIR) is considered to play a pivotal role. However, the link between HIR and brain injury remains unclear. Because circulating exosomes are considered as the key mediators of information transmission over long distances, we aimed to assess the role of circulating exosomes in HIR-induced hippocampal injury in young rats.

METHODS

We administered exosomes extracted from the sera of HIR model rats to normal young rats via the tail vein. Western blotting, enzyme-linked immunosorbent assay, histological examination, and real-time quantitative polymerase chain reaction were used to evaluate the role of exosomes in neuronal injury and activation of microglial pyroptosis in the developing hippocampus. Primary microglial cells were cocultured with exosomes to further assess the effect of exosomes on microglia. To further explore the potential mechanism, GW4869 or MCC950 was used to block exosome biogenesis or nod-like receptor family protein 3, respectively.

RESULTS

Serum-derived exosomes played a crucial role in linking HIR with neuronal degeneration in the developing hippocampus. Microglia were found to be the target cells of ischemia-reperfusion derived exosomes (I/R-exosomes). I/R-exosomes were taken up by microglia and promoted the occurrence of microglial pyroptosis in vivo and in vitro. Moreover, the exosome-induced neuronal injury was alleviated by suppressing the occurrence of pyroptosis in the developing hippocampus.

CONCLUSIONS

Microglial pyroptosis induced by circulating exosomes plays a vital role in developing hippocampal neuron injury during HIR in young rats.

Insight into extracellular vesicles in vascular diseases: intercellular communication role and clinical application potential

BACKGROUND

Cells have been increasingly known to release extracellular vesicles (EVs) to the extracellular environment under physiological and pathological conditions. A plethora of studies have revealed that EVs contain cell-derived biomolecules and are found in circulation, thereby implicating them in molecular trafficking between cells. Furthermore, EVs have an effect on physiological function and disease development and serve as disease biomarkers.

MAIN BODY

Given the close association  between EV circulation and vascular disease, this review aims to provide a brief introduction to EVs, with a specific focus on the EV cargoes participating in pathological mechanisms, diagnosis, engineering, and clinical potential, to highlight the emerging evidence suggesting promising targets in vascular diseases. Despite the expansion of research in this field, some noticeable limitations remain for clinical translational research.

CONCLUSION

This review makes a novel contribution to a summary of recent advances and a perspective on the future of EVs in vascular diseases. Video Abstract.

The m6A reader YTHDF2 alleviates the inflammatory response by inhibiting IL-6R/JAK2/STAT1 pathway-mediated high-mobility group box-1 release

Background

Sepsis is a common severe complication in major burn victims and is characterized by a dysregulated systemic response to inflammation. YTH domain family 2 (YTHDF2), a well-studied N6-methyladenosine (m6A) reader that specifically recognizes and binds to m6A-modified transcripts to mediate their degradation, is connected to pathogenic and physiological processes in eukaryotes, but its effect on sepsis is still unknown. We aimed to discover the effects and mechanisms of YTHDF2 in sepsis.

Methods

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot analyses were used to measure the expression of YTHDF2, the interleukin 6 receptor (IL-6R), high-mobility group box-1 (HMGB1), Janus kinase 2 (JAK2) and signal transducer and activator of transcription 1 (STAT1) under different in vitro conditions. Enzyme-linked immunosorbent assays were utilized to evaluate the expression of HMGB1, IL-6, IL-1β and tumor necrosis factor-α. To confirm that YTHDF2 specifically targets IL-6R mRNA, RNA immunoprecipitation and dual-luciferase reporter assays were performed. Finally, we utilized a mouse model of lipopolysaccharide (LPS)-induced sepsis to verify the effects of YTHDF2 in vivo.

Results

According to our findings, YTHDF2 was expressed at a low level in peripheral blood mononuclear cells from septic mice and patients as well as in LPS-induced RAW264.7 cells. Overexpression of YTHDF2 alleviated the inflammatory response by inhibiting HMGB1 release and JAK2/STAT1 signalling in LPS-stimulated cells. Mechanistically, YTHDF2 suppressed JAK2/STAT1 signalling by directly recognizing the m6A-modified site in IL-6R and decreasing the stability of IL-6R mRNA, thereby inhibiting HMGB1 release. In vivo experiments showed that YTHDF2 played a protective role in septic mice by suppressing the IL-6R/JAK2/STAT1/HMGB1 axis.

Conclusions

In summary, these findings demonstrate that YTHDF2 plays an essential role as an inhibitor of inflammation to reduce the release of HMGB1 by inhibiting the IL-6R/JAK2/STAT1 pathway, indicating that YTHDF2 is a novel target for therapeutic interventions in sepsis.

Small extracellular vesicles delivering lncRNA WAC-AS1 aggravate renal allograft ischemia‒reperfusion injury by inducing ferroptosis propagation

Ferroptosis is a predominant contributor to renal ischemia reperfusion injury (IRI) after kidney transplant, evoking delayed graft function and poorer long-term outcomes. The wide propagation of ferroptosis among cell populations in a wave-like manner, developing the "wave of ferroptosis" causes a larger area of tubular necrosis and accordingly aggravates renal allograft IRI. In this study, we decipher a whole new metabolic mechanism underlying ferroptosis and propose a novel spreading pathway of the "wave of ferroptosis" in the renal tissue microenvironment, in which renal IRI cell-secreted small extracellular vesicles (IRI-sEVs) delivering lncRNA WAC-AS1 reprogram glucose metabolism in adjacent renal tubular epithelial cell populations by inducing GFPT1 expression and increasing hexosamine biosynthesis pathway (HBP) flux, and consequently enhances O-GlcNAcylation. Additionally, BACH2 O-GlcNAcylation at threonine 389 in renal tubular epithelial cells prominently inhibits its degradation by ubiquitination and promotes importin α5-mediated nuclear translocation. We present the first evidence that intranuclear BACH2 suppresses SLC7A11 and GPX4 transcription by binding to their proximal promoters and decreases cellular anti-peroxidation capability, accordingly facilitating ferroptosis. Inhibition of sEV biogenesis and secretion by GW4869 and knockout of lncRNA WAC-AS1 in IRI-sEVs both unequivocally diminished the "wave of ferroptosis" propagation and protected against renal allograft IRI. The functional and mechanistic regulation of IRI-sEVs was further corroborated in an allograft kidney transplant model and an in situ renal IRI model. In summary, these findings suggest that inhibiting sEV-mediated lncRNA WAC-AS1 secretion and targeting HBP metabolism-induced BACH2 O-GlcNAcylation in renal tubular epithelial cells may serve as new strategies for protecting against graft IRI after kidney transplant.

A bibliometric analysis of myocardial ischemia/reperfusion injury from 2000 to 2023

Background

Myocardial ischemia/reperfusion injury (MIRI) refers to the more severe damage that occurs in the previously ischemic myocardium after a short-term interruption of myocardial blood supply followed by restoration of blood flow within a certain period of time. MIRI has become a major challenge affecting the therapeutic efficacy of cardiovascular surgery.

Methods

A scientific literature search on MIRI-related papers published from 2000 to 2023 in the Web of Science Core Collection database was conducted. VOSviewer was used for bibliometric analysis to understand the scientific development and research hotspots in this field.

Results

A total of 5,595 papers from 81 countries/regions, 3,840 research institutions, and 26,202 authors were included. China published the most papers, but the United States had the most significant influence. Harvard University was the leading research institution, and influential authors included Lefer David J., Hausenloy Derek J., Yellon Derek M., and others. All keywords can be divided into four different directions: risk factors, poor prognosis, mechanisms and cardioprotection.

Conclusion

Research on MIRI is flourishing. It is necessary to conduct an in-depth investigation of the interaction between different mechanisms and multi-target therapy will be the focus and hotspot of MIRI research in the future.

Exosomal Non-Coding RNA Mediates Macrophage Polarization: Roles in Cardiovascular Diseases

Extracellular vesicles (EVs) or exosomes are nanosized extracellular particles that contain proteins, DNA, non-coding RNA (ncRNA) and other molecules, which are widely present in biofluids throughout the body. As a key mediator of intercellular communication, EVs transfer their cargoes to target cells and activate signaling transduction. Increasing evidence shows that ncRNA is involved in a variety of pathological and physiological processes through various pathways, particularly the inflammatory response. Macrophage, one of the body's "gatekeepers", plays a crucial role in inflammatory reactions. Generally, macrophages can be classified as pro-inflammatory type (M1) or anti-inflammatory type (M2) upon their phenotypes, a phenomenon termed macrophage polarization. Increasing evidence indicates that the polarization of macrophages plays important roles in the progression of cardiovascular diseases (CVD). However, the role of exosomal ncRNA in regulating macrophage polarization and the role of polarized macrophages as an important source of EV in CVD remains to be elucidated. In this review, we summarize the role and molecular mechanisms of exosomal-ncRNA in regulating macrophage polarization during CVD development, focusing on their cellular origins, functional cargo, and their detailed effects on macrophage polarization. We also discuss the role of polarized macrophages and their derived EV in CVD as well as the therapeutic prospects of exosomal ncRNA in the treatment of CVD.

Assessment of circulating extracellular vesicles from calorie-restricted mice and humans in ischaemic injury models

Calorie restriction (CR) and fasting affect lifespan, disease susceptibility and response to acute injury across multiple animal models, including ischaemic injuries such as myocardial infarction or kidney hypoxia. The cargo and function of circulating extracellular vesicles (EV) respond to changes in host physiology, including exercise, injury, and other interventions. Thus, we hypothesised that EVs induced following CR may reflect some of the beneficial properties of CR itself. In a pilot study, EVs were isolated from mice following 21 days of 30 % CR, and from eight human donors after 72 h water-only fasting. EV size, concentration and morphology were profiled by NTA, western blot and cryoEM, and their function was assessed using multiple assays related to ischaemic diseases. We found that EVs from post-fasting samples better protected cardiac cells from hypoxia/reperfusion (H/R) injury compared to pre-fasting EVs. However, there was no difference when used to treat H/R-injured kidney epithelial cells. Post-fasting derived EVs slowed the rate of fibroblast migration and slightly reduced macrophage inflammatory gene expression compared to pre-fasting derived EVs. Lastly, we compared miRNA cargos of pre- and post-fasting human serum EVs and found significant changes in a small number of miRNAs. We conclude that fasting appears to influence EV cargo and function, with varied effects worthy of further exploration.

Identification of the microRNA alterations in extracellular vesicles derived from human haemorrhoids

NEW FINDINGS

What is the central question of this study? What are the morphological features and microRNA (miRNA) expression features of extracellular vesicles (EVs) from haemorrhoids (Hae-EVs) and normal tissues? What are the potential functions of the differentially expressed (DE) miRNAs in Hae-EVs? What is the main finding and its importance? We present, for the first time, the morphological features and miRNA profile of human Hae-EVs. Four hundred and forty-seven significant DE-miRNAs were identified. Gene ontology and pathway analysis of the DE-miRNAs indicated diverse roles of the Hae-EVs through different pathways. Our findings provide EV-based pathological features and the underlying mechanism of haemorrhoids.

ABSTRACT

Extracellular vesicles (EVs) play important roles in many pathophysiologies as cell-to-cell communication vehicles. However, the features and potential functions of the EVs in haemorrhoids remain unclear. Therefore, we performed microRNA (miRNA) microarray analysis in EVs derived from haemorrhoid tissue to identify the profile of miRNAs in these EVs and predict their potential functions. We obtained typical EVs from both haemorrhoid and control tissues. Microarray analysis identified 447 miRNAs with significant differential expresssion (DE): 245 upregulated and 202 downregulated. The top three upregulated miRNAs in haemorrhoid EVs (Hae-EVs), namely miR-6741-3p, miR-6834-3p and miR-4254, were detected by RT-qPCR in both Hae-EVs and haemorrhoid tissues. Interestingly, we found a different expression pattern in the haemorrhoid tissues from that in Hae-EVs. The potential target genes of these DE-miRNAs were predicted by the miRWalk and miRDB databases. Gene ontology (GO) analysis of the target genes showed that the DE-miRNAs contributed mainly to protein kinase activity, transcriptional activity and ubiquitin-protein function. KEGG search found that the DE-miRNAs might regulate the MAPK and Ras signalling pathways. These findings revealed, for the first time, the miRNA profiles in Hae-EVs and provided potential targets and pathways involved in the pathological process.

Intravenously Administered Human Umbilical Cord-Derived Mesenchymal Stem Cell (HucMSC) Improves Cardiac Performance following Infarction via Immune Modulation

Overactive inflammatory responses contribute to progressive cardiac dysfunction after myocardial infarction (MI). Mesenchymal stem cell (MSC) has generated significant interest as potent immune modulators that can regulate excessive immune responses. We hypothesized that intravenous (iv) administration of human umbilical cord-derived MSC (HucMSC) exerts systemic and local anti-inflammation effects, leading to improved heart function after MI. In murine MI models, we confirmed that single iv administration of HucMSC ( $30\times {10}^4$ ) improved cardiac performance and prevented adverse remodeling after MI. A small proportion of HucMSC is trafficked to the heart, preferentially in the infarcted region. HucMSC administration increased CD3+ T cell proportion in the periphery while decreased T cell proportion in both infarcted heart and mediastinal lymph nodes (med-LN) at 7-day post-MI, indicating a systematic and local T cell interchange mediated by HucMSC. The inhibitory effects of HucMSC on T cell infiltration in the infarcted heart and med-LN sustained to 21-day post-MI. Our findings suggested that iv administration of HucMSC fostered systemic and local immunomodulatory effects that contributed to the improvement of cardiac performance after MI.

IGFBP2 derived from PO-MSCs promote epithelial barrier destruction by activating FAK signaling in nasal polyps

The nasal polyps (NPs) microenvironment comprises multiple cell types, including mesenchymal stromal cells (MSCs). Insulin-like growth factor binding protein 2 (IGFBP2) plays crucial roles in cell proliferation, differentiation and more. However, the role of NPs-derived MSCs (PO-MSCs) and IGFBP2 in NPs pathogenesis remains poorly defined. Herein, primary human nasal epithelial cells (pHNECs) and MSCs were extracted and cultured. Extracellular vesicles (EVs) and soluble proteins were isolated to investigate the role of PO-MSCs on epithelial-mesenchymal transition (EMT) and epithelial barrier function in NPs. Our data showed that IGFBP2, but not EVs from PO-MSCs (PO-MSCs-EVs), exhibited a crucial role in EMT and barrier destruction. Moreover, focal adhesion kinase (FAK) signaling pathway is necessary for IGFBP2 to exert its functions in human and mice nasal epithelial mucosa. Altogether, these findings may improve the current understanding of the role of PO-MSCs in NPs microenvironment and ultimately contribute to the prevention and treatment of NPs.

MicroRNA-155-5p in serum derived-exosomes promotes ischaemia-reperfusion injury by reducing CypD ubiquitination by NEDD4

AIMS

Recovery of blood flow is a therapeutic approach for myocardial infarction but paradoxically induces injury to the myocardium. Exosomes (exos) are pivotal mediators for intercellular communication that can be released by different cells and are involved in cardiovascular diseases. This study aimed to explore the possible effects and mechanisms of miR-155-5p loaded by serum-derived exos in myocardial infarction reperfusion injury (MIRI).

METHODS AND RESULTS

Exos were isolated from mouse serum after induction of ischaemia reperfusion (I/R) and injected into I/R-treated mice to assess cardiac function, infarction size, and cardiomyocyte apoptosis. Primary cardiomyocytes were transfected with miR-155-5p inhibitor before treatment with oxygen-glucose deprivation and re-oxygenation (OGD/R) and exos derived from the serum of I/R-treated mice (I/R-Exos), in which Bcl-2, Bax, and cleaved-caspase-3 levels were detected. The interactions among miR-155-5p, NEDD4, and CypD were evaluated. miR-155-5p level was evidently increased in I/R-Exos than in exos from the serum of sham-operated mice (P < 0.05). In comparison with the I/R group, the I/R-Exos + I/R group had increased infarct size, elevated miR-155-5p expression, and boosted apoptotic rate in mouse myocardium (P < 0.05). In mice treated with I/R-Exos and I/R, miR-155-5p inhibition reduced cardiac infarct size and apoptosis (P < 0.05). NEDD4 was a target gene of miR-155-5p and promoted CypD ubiquitination. Cardiomyocyte apoptosis was markedly increased in the miR-155-5p inhibitor + shNEDD4 + OGD/R group versus the miR-155-5p inhibitor + OGD/R group (P < 0.05), but decreased in the miR-155-5p inhibitor + shNEDD4 + shCypD + OGD/R group than in the miR-155-5p inhibitor + shNEDD4 + OGD/R group (P < 0.05).

CONCLUSIONS

miR-155-5p in I/R-Exos may facilitate MIRI by inhibiting CypD ubiquitination via targeting NEDD4.

Bardoxolone Methyl Ameliorates Myocardial Ischemia/Reperfusion Injury by Activating the Nrf2/HO-1 Signaling Pathway

Background

Myocardial ischemia/reperfusion (I/R) injury is a severe heart problem resulting from restoring coronary blood flow to the myocardium after ischemia. This study is aimed at ascertaining the therapeutic efficiency and action mechanism of bardoxolone methyl (BARD) in myocardial I/R injury.

Methods

In male rats, myocardial ischemia was performed for 0.5 h, and then, reperfusion lasted for 24 h. BARD was administrated in the treatment group. The animal's cardiac function was measured. Myocardial I/R injury serum markers were detected via ELISA. The 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to estimate the infarction. H&E staining was used to evaluate the cardiomyocyte damage, and Masson trichrome staining was used to observe the proliferation of collagen fiber. The apoptotic level was assessed via the caspase-3 immunochemistry and TUNEL staining. Oxidative stress was measured through malondialdehyde, 8-hydroxy-2'-deoxyguanosine, superoxide dismutase, and inducible nitric oxide synthases. The alteration of the Nrf2/HO-1 pathway was confirmed via western blot, immunochemistry, and PCR analysis.

Results

The protective effect of BARD on myocardial I/R injury was observed. In detail, BARD decreased cardiac injuries, reduced cardiomyocyte apoptosis, and inhibited oxidative stress. For mechanisms, BARD treatment significantly activates the Nrf2/HO-1 pathway.

Conclusion

BARD ameliorates myocardial I/R injury by inhibiting oxidative stress and cardiomyocyte apoptosis via activating the Nrf2/HO-1 pathway.

Exploring Myocardial Ischemia-Reperfusion Injury Mechanism of Cinnamon by Network Pharmacology, Molecular Docking, and Experiment Validation

Myocardial ischemia-reperfusion injury (MIRI) is a common complication of acute myocardial infarction that seriously endangers human health. Cinnamon, a traditional Chinese medicine, has been used to counteract MIRI as it has been shown to possess anti-inflammatory and antioxidant properties. To investigate the mechanisms of action of cinnamon in the treatment of MIRI, a deep learning-based network pharmacology method was established to predict potential active compounds and targets. The results of the network pharmacology showed that oleic acid, palmitic acid, beta-sitosterol, eugenol, taxifolin, and cinnamaldehyde were the main active compounds, and phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt), mitogen-activated protein kinase (MAPK), interleukin (IL)-7, and hypoxia-inducible factor 1 (HIF-1) are promising signaling pathways. Further molecular docking tests revealed that these active compounds and targets exhibited good binding abilities. Finally, experimental validation using a zebrafish model demonstrated that taxifolin, the active compound of cinnamon, has a potential protective effect against MIRI.

Extracellular vesicles mediate biological information delivery: A double-edged sword in cardiac remodeling after myocardial infarction

Acute myocardial infarction (AMI) is a severe ischemic disease with high morbidity and mortality worldwide. Maladaptive cardiac remodeling is a series of abnormalities in cardiac structure and function that occurs following myocardial infarction (MI). The pathophysiology of this process can be separated into two distinct phases: the initial inflammatory response, and the subsequent longer-term scar revision that includes the regression of inflammation, neovascularization, and fibrotic scar formation. Extracellular vesicles are nano-sized lipid bilayer vesicles released into the extracellular environment by eukaryotic cells, containing bioinformatic transmitters which are essential mediators of intercellular communication. EVs of different cellular origins play an essential role in cardiac remodeling after myocardial infarction. In this review, we first introduce the pathophysiology of post-infarction cardiac remodeling, as well as the biogenesis, classification, delivery, and functions of EVs. Then, we explore the dual role of these small molecule transmitters delivered by EVs in post-infarction cardiac remodeling, including the double-edged sword of pro-and anti-inflammation, and pro-and anti-fibrosis, which is significant for post-infarction cardiac repair. Finally, we discuss the pharmacological and engineered targeting of EVs for promoting heart repair after MI, thus revealing the potential value of targeted modulation of EVs and its use as a drug delivery vehicle in the therapeutic process of post-infarction cardiac remodeling.

Research advances and challenges in tissue-derived extracellular vesicles

Extracellular vesicles (EV) are vesicular vesicles with phospholipid bilayer, which are present in biological fluids and extracellular microenvironment. Extracellular vesicles serve as pivotal mediators in intercellular communication by delivering lipids, proteins, and RNAs to the recipient cells. Different from extracellular vesicles derived from biofluids and that originate from cell culture, the tissue derived extracellular vesicles (Ti-EVs) send us more enriched and accurate information of tissue microenvironment. Notably, tissue derived extracellular vesicles directly participate in the crosstalk between numerous cell types within microenvironment. Current research mainly focused on the extracellular vesicles present in biological fluids and cell culture supernatant, yet the studies on tissue derived extracellular vesicles are increasing due to the tissue derived extracellular vesicles are promising agents to reflect the occurrence and development of human diseases more accurately. In this review, we aimed to clarify the characteristics of tissue derived extracellular vesicles, specify the isolation methods and the roles of tissue derived extracellular vesicles in various diseases, including tumors. Moreover, we summarized the advances and challenges of tissue derived extracellular vesicles research.

CD44 promotes angiogenesis in myocardial infarction through regulating plasma exosome uptake and further enhancing FGFR2 signaling transduction

BACKGROUND

Since angiogenesis occurs as the pathological process following myocardial infarction to alleviate ischemia, therapeutic angiogenesis has been proposed to be a cardioprotective strategy. CD44 has been implicated in endothelial cell functions and its role has been well established in angiogenesis for years. Although recent studies indicate the close correlation between CD44 and exosome, as well as the two being implicated in myocardial ischemia pathological processes, the effect and the underlying mechanism of CD44 and its regulated plasma exosome in pathological angiogenesis post-myocardial infarction have not been fully elucidated.

METHODS

In this study, we used CD44 knockout mice to study the in vivo impacts of CD44 on ischemic angiogenesis in myocardial infarction. Mouse cardiac function was measured by echocardiography, histological changes were observed by Evans Blue and TTC-double staining and Masson's trichrome staining, and molecular changes were detected by immunofluorescence. In the in vitro study, CD44 knockout HUVECs were generated and CD44 inhibitor was used to study the mechanism of CD44 on angiogenesis. We performed the immunoprecipitation, proximity ligation assay, and super-resolution imaging to study the mechanistic regulation of FGFR2 signaling transduction by CD44. Importantly, we also isolated plasma exosomes from myocardial infarction model mice and studied the effect of plasma exosomes on the activation of the FGFR2 signaling pathway and the related phenotypic alterations, including exosomes uptake and angiogenic function in primary mouse microvascular endothelial cells, and further discovered the regulation mechanism of exosomal miRNAs.

RESULTS

We observed that the expression of CD44 in the border zone of the infarcted heart was tightly related to pathological angiogenesis following myocardial ischemia. The depletion of CD44 impaired angiogenesis and impacts biogenesis and proangiogenic function of plasma exosomes. Subsequently, we found that CD44 mediated the activation of the FGFR2 signaling pathway as well as the caveolin 1-dependent uptake of exosomes in vascular endothelial cells. Most importantly, the proangiogenic therapeutic effect of plasma exosomal miRNAs depended upon the participation of CD44/FGFR2 signaling transduction in vascular endothelial cells.

CONCLUSION

CD44 and its regulated plasma exosomes have crucial potent angiogenic activity. Our studies elucidate that CD44 plays a key role in plasma exosomal miRNA-enhanced angiogenic FGFR2 singling transduction and ischemic angiogenesis in the early stage of myocardial infarction.

Shenlian extract attenuates myocardial ischaemia-reperfusion injury via inhibiting M1 macrophage polarization by silencing miR-155

CONTEXT

Shenlian extract (SL) is a combination of Salvia miltiorrhiza Bge. (Labiatae) and Andrographis paniculata (Burm. F.) Wall. Ex Nees (Acanthaceae) extracts, which promote blood circulation and clear endogenous heat toxins. Myocardial ischaemia-reperfusion injury (MI/RI) is aggravated myocardial tissue damage induced by reperfusion therapy after myocardial infarction.

OBJECTIVES

This study explores the effect of SL on MI/RI and the underlying mechanism.

MATERIALS AND METHODS

Primary peritoneal macrophages (pMACs) were treated with LPS and SL (5, 10 or 20 μg/mL) for 24 h. The myocardial ischaemia-reperfusion (MI/R) model was established after administration of different doses of SL (90, 180 or 360 mg/kg). Myocardial tissue injury was assessed by methylthiazolyl tetrazolium (TTC) staining and levels of creatine kinase (CK), lactate dehydrogenase (LDH) and superoxide dismutase (SOD) in mice. The double immunofluorescence staining of iNOS/F4/80 and CD86/F4/80 was used to detect macrophage M1 polarization. The levels of miR-155, inflammatory factors and chemokines were detected by qRT-PCR or ELISA. CD86, iNOS, SOCS3, JAK2, p-JAK2, STAT3 and p-STAT3 proteins expressions in macrophages were analyzed by western blotting. Conditioned medium transfer systems were designed to unite M1 macrophages with H/R cardiomyocytes, and cell apoptosis was detected by TUNEL staining, western blotting or immunohistochemistry.

RESULTS

SL reduced apoptosis, diminished CK and LDH levels, raised SOD concentration and decreased infarct size in the MI/R model. Meanwhile, SL decreased miR-155 level, inhibited M1 macrophage polarization and inflammation. Furthermore, SL promoted SOCS3 expression and blocked JAK2/STAT3 pathway in vitro.

CONCLUSIONS

SL may be a promising TCM candidate for MI/RI. The underlying mechanisms could be associated with inhibition of M1 macrophage polarization via down-regulating miR-155.

Research Progress on the Role of Pyroptosis in Myocardial Ischemia-Reperfusion Injury

Myocardial ischemia-reperfusion injury (MIRI) results in the aggravation of myocardial injury caused by rapid recanalization of the ischemic myocardium. In the past few years, there is a growing interest in investigating the complex pathophysiological mechanism of MIRI for the identification of effective targets and drugs to alleviate MIRI. Currently, pyroptosis, a type of inflammatory programmed death, has received greater attention. It is involved in the MIRI development in combination with other mechanisms of MIRI, such as oxidative stress, calcium overload, necroptosis, and apoptosis, thereby forming an intertwined association between different pathways that affect MIRI by regulating common pathway molecules. This review describes the pyroptosis mechanism in MIRI and its relationship with other mechanisms, and also highlights non-coding RNAs and non-cardiomyocytes as regulators of cardiomyocyte pyroptosis by mediating associated pathways or proteins to participate in the initiation and development of MIRI. The research progress on novel small molecule drugs, clinical drugs, traditional Chinese medicine, etc. for regulating pyroptosis can play a crucial role in effective MIRI alleviation. When compared to research on other mature mechanisms, the research studies on pyroptosis in MIRI are inadequate. Although many related protective drugs have been identified, these drugs generally lack clinical applications. It is necessary to further explore and verify these drugs to expand their applications in clinical setting. Early inhibition of MIRI by targeted regulation of pyroptosis is a key concern that needs to be addressed in future studies.

KDM3A Attenuates Myocardial Ischemic and Reperfusion Injury by Ameliorating Cardiac Microvascular Endothelial Cell Pyroptosis

Cardiac microvascular endothelial cell ischemia-reperfusion (CMEC I/R) injury occurs in approximately 50% of acute myocardial infarction patients subjected to successful revascularization therapy. This injury leads to cardiac microcirculatory system dysfunctions, which seriously affect cardiac functions and long-term prognostic outcomes. Previously, we elucidated the role of lysine-specific demethylase 3A (KDM3A) in protecting cardiomyocytes from I/R injury; however, its roles in CMEC I/R injuries have yet to be fully established. In this study, hypoxia/reoxygenation (H/R) treatment significantly impaired CMEC functions and induced their pyroptosis, accompanied by KDM3A downregulation. Then, gain- and loss-of-function assays were performed to investigate the roles of KDM3A in CMEC H/R injury in vitro. KDM3A knockout enhanced CMEC malfunctions and accelerated the expressions of pyroptosis-associated proteins, such as NLRP3, cleaved-caspase-1, ASC, IL-1β, GSDMD-N, and IL-18. Conversely, KDM3A overexpression developed ameliorated alternations in CMEC H/R injury. In vivo, KDM3A knockout resulted in the deterioration of cardiac functions and decreased the no-reflow area as well as capillary density. Mechanistically, KDM3A activated the PI3K/Akt signaling pathway and ameliorated I/R-mediated CMEC pyroptosis. In conclusion, KDM3A is a promising treatment target for alleviating CMEC I/R injury.

An injectable co-assembled hydrogel blocks reactive oxygen species and inflammation cycle resisting myocardial ischemia-reperfusion injury

The overproduction of reactive oxygen species (ROS) and burst of inflammation following cardiac ischemia-reperfusion (I/R) are the leading causes of cardiomyocyte injury. Monotherapeutic strategies designed to enhance anti-inflammatory or anti-ROS activity explicitly for treating I/R injury have demonstrated limited success because of the complex mechanisms of ROS production and induction of inflammation. Intense oxidative stress leads to sustained injury, necrosis, and apoptosis of cardiomyocytes. The damaged and necrotic cells can release danger-associated molecular patterns (DAMPs) that can cause the aggregation of immune cells by activating Toll-like receptor 4 (TLR4). These immune cells also promote ROS production by expressing NADPH oxidase. Finally, ROS production and inflammation form a vicious cycle, and ROS and TLR4 are critical nodes of this cycle. In the present study, we designed and prepared an injectable hydrogel system of EGCG@Rh-gel by co-assembling epigallocatechin-3-gallate (EGCG) and the rhein-peptide hydrogel (Rh-gel). The co-assembled hydrogel efficiently blocked the ROS-inflammation cycle by ROS scavenging and TLR4 inhibition. Benefited by the abundant noncovalent interactions of π-π stacking and hydrogen bonding between EGCG and Rh-gel, the co-assembled hydrogel had good mechanical strength and injectable property. Following the injection EGCG@Rh-gel into the damaged region of the mice's heart after I/R, the hydrogel enabled to achieve long-term sustained release and treatment, improve cardiac function, and significantly reduce the formation of scarring. Further studies demonstrated that these beneficial outcomes arise from the reduction of ROS production, inhibition of inflammation, and induction of anti-apoptosis in cardiomyocytes. Therefore, EGCG@Rh-gel is a promising drug delivery system to block the ROS-inflammation cycle for resisting myocardial I/R injury. STATEMENT OF SIGNIFICANCE: 1. Monotherapeutic strategies designed to enhance anti-inflammatory or anti-ROS effects for treating I/R injury have demonstrated limited success because of the complex mechanisms of ROS and inflammation. 2. ROS production and inflammation form a vicious cycle, and ROS and TLR4 are critical nodes of this cycle. 3. Here, we designed an injectable hydrogel system of EGCG@Rh-gel by co-assembling epigallocatechin-3-gallate (EGCG) and a rhein-peptide hydrogel (Rh-gel). EGCG@Rh-gel efficiently blocked the ROS-inflammation cycle by ROS scavenging and TLR4 inhibition. 4. EGCG@Rh-gel achieved long-term sustained release and treatment, improved cardiac function, and significantly reduced the formation of scarring after I/R. 5. The beneficial outcomes arise from reducing ROS production, inhibiting inflammation, and inducing anti-apoptosis in cardiomyocytes.

Extracellular Vesicle/Macrophage Axis: Potential Targets for Inflammatory Disease Intervention

Extracellular vesicles (EVs) can regulate the polarization of macrophages in a variety of inflammatory diseases by mediating intercellular signal transduction and affecting the occurrence and development of diseases. After macrophages are regulated by EVs, they mainly show two phenotypes: the proinflammatory M1 type and the anti-inflammatory M2 type. A large number of studies have shown that in diseases such as mastitis, inflammatory bowel disease, Acute lung injury, and idiopathic pulmonary fibrosis, EVs promote the progression of the disease by inducing the M1-like polarization of macrophages. In diseases such as liver injury, asthma, and myocardial infarction, EVs can induce M2-like polarization of macrophages, inhibit the inflammatory response, and reduce the severity of the disease, thus indicating new pathways for treating inflammatory diseases. The EV/macrophage axis has become a potential target for inflammatory disease pathogenesis and comprehensive treatment. This article reviews the structure and function of the EV/macrophage axis and summarizes its biological functions in inflammatory diseases to provide insights for the diagnosis and treatment of inflammatory diseases.

Nanocarrier-Based Targeted Therapies for Myocardial Infarction

Myocardial infarction is a major cause of morbidity and mortality worldwide. Due to poor inherent regeneration of the adult mammalian myocardium and challenges with effective drug delivery, there has been little progress in regenerative therapies. Nanocarriers, including liposomes, nanoparticles, and exosomes, offer many potential advantages for the therapy of myocardial infarction, including improved delivery, retention, and prolonged activity of therapeutics. However, there are many challenges that have prevented the widespread clinical use of these technologies. This review aims to summarize significant principles and developments in the field, with a focus on nanocarriers using ligand-based or cell mimicry-based targeting. Lastly, a discussion of limitations and potential future direction is provided.

Extracellular vesicle-packaged mitochondrial disturbing miRNA exacerbates cardiac injury during acute myocardial infarction

Mounting evidence suggests that extracellular vesicles (EVs) are effective communicators in biological signalling in cardiac physiology and pathology. However, the role of EVs in cardiac injury, particularly in ischemic myocardial scenarios, has not been fully elucidated. Here, we report that acute myocardial infarction (AMI)‐induced EVs can impair cardiomyocyte survival and exacerbate cardiac injury. EV‐encapsulated miR‐503, which is enriched during the early phase of AMI, is a critical molecule that mediates myocardial injury. Functional studies revealed that miR‐503 promoted cardiomyocyte death by directly binding to peroxisome proliferator‐activated receptor gamma coactivator‐1β (PGC‐1β) and a mitochondrial deacetylase, sirtuin 3 (SIRT3), thereby triggering mitochondrial metabolic dysfunction and cardiomyocyte death. Mechanistically, we identified endothelial cells as the primary source of miR‐503 in EVs after AMI. Hypoxia induced rapid H3K4 methylation of the promoter of the methyltransferase‐like 3 gene (METTL3) and resulted in its overexpression. METTL3 overexpression evokes N6‐methyladenosine (m⁶A)‐dependent miR‐503 biogenesis in endothelial cells. In summary, this study highlights a novel endogenous mechanism wherein EVs aggravate myocardial injury during the onset of AMI via endothelial cell‐secreted miR‐503 shuttling.

Oxycodone protects cardiac microvascular endothelial cells against ischemia/reperfusion injury by binding to Sigma-1 Receptor

Endothelial dysfunction is an important mechanism involved in myocardial ischemia-reperfusion (I/R) injury. We aimed to explore the effects of Oxycodone on myocardial I/R injury in vivo and in vitro to reveal its mechanisms related to Sigma-1 Receptor (SIGMAR1). A rat model of I/R-induced myocardial injury was developed. The ischemic area and myocardial histopathological changes after oxycodone addition were evaluated by TTC staining and H&E staining. LDH, CK-MB and cTnI levels were used to assess myocardial function. Then, the endothelial integrity was reflected by the expressions of ZO-1, Claudin-1 and Occludin. Afterward, ELISA, RT-qPCR, western blot and immunofluorescence assays were adopted for the detection of inflammation-related genes. SIGMAR1 expression in myocardial tissues induced by I/R and cardiac microvascular endothelial cells (CMECs) under hypoxic/reoxygenation (H/R) was determined using RT-qPCR and western blotting. Subsequently, after SIGMAR1 silencing or BD1047 addition (a SIGMAR1 antagonist), cell apoptosis and endothelial integrity were analyzed in the presence of Oxycodone in H/R-stimulated CMECs. Results indicated that Oxycodone decreased the ischemic area and improved myocardial function in myocardial I/R injury rat. Oxycodone improved myocardial histopathological injury and elevated endothelial integrity, evidenced by upregulated ZO-1, Claudin-1 and Occludin expressions. Moreover, inflammatory response was alleviated after Oxycodone administration. Molecular docking suggested that SIGMAR1 could directly bind to Oxycodone. Oxycodone elevated SIGMAR1 expression and SIGMAR1 deletion or BD1047 addition attenuated the impacts of Oxycodone on apoptosis and endothelial integrity of CMECs induced by H/R. Collectively, Oxycodone alleviates myocardial I/R injury in vivo and in vitro by binding to SIGMAR1.

Nrf2 Promotes Inflammation in Early Myocardial Ischemia-Reperfusion via Recruitment and Activation of Macrophages

Cardiomyocyte apoptosis in response to inflammation is a primary cause of myocardial ischemia-reperfusion injury (IRI). Nuclear factor erythroid 2 like 2 (Nrf2) reportedly plays an important role in myocardial IRI, but the underlying mechanism remains obscure. Expression data from the normal heart tissues of mice or heart tissues treated with reperfusion for 6 h after ischemia (IR6h) were acquired from the GEO database; changes in biological function and infiltrating immune cells were analyzed. The binding between the molecules was verified by chromatin immunoprecipitation sequencing. Based on confirmation that early myocardial ischemia-reperfusion (myocardial ischemia/reperfusion for 6 hours, IR6h) promoted myocardial apoptosis and inflammatory response, we found that Nrf2, cooperating with Programmed Cell Death 4, promoted transcription initiation of C-C Motif Chemokine Ligand 3 (Ccl3) in myocardial tissues of mice treated with IR6h. Moreover, Ccl3 contributed to the high signature score of C-C motif chemokine receptor 1 (Ccr1)-positive macrophages. The high signature score of Ccr1-positive macrophages leads to the release of pro-inflammatory factors interleukin 1 beta and interleukin 6. This study is the first to elucidate the damaging effect of Nrf2 via remodeling of the immune microenvironment in early myocardial ischemia-reperfusion, which provides us with new perspectives and treatment strategies for myocardial ischemia-reperfusion.

Impact of the Main Cardiovascular Risk Factors on Plasma Extracellular Vesicles and Their Influence on the Heart's Vulnerability to Ischemia-Reperfusion Injury

The majority of cardiovascular deaths are associated with acute coronary syndrome, especially ST-elevation myocardial infarction. Therapeutic reperfusion alone can contribute up to 40 percent of total infarct size following coronary artery occlusion, which is called ischemia-reperfusion injury (IRI). Its size depends on many factors, including the main risk factors of cardiovascular mortality, such as age, sex, systolic blood pressure, smoking, and total cholesterol level as well as obesity, diabetes, and physical effort. Extracellular vesicles (EVs) are membrane-coated particles released by every type of cell, which can carry content that affects the functioning of other tissues. Their role is essential in the communication between healthy and dysfunctional cells. In this article, data on the variability of the content of EVs in patients with the most prevalent cardiovascular risk factors is presented, and their influence on IRI is discussed.